Acta radiologica: therapy, physics, biology最新文献

A computer program is described for central axis dose calculations for 60Co and 6 MV photons. Fixed distance or isocentric calculations for regular or irregular fields can be performed. Corrections are made for wedges and blocking trays. Tissue-air ratios and percentage depth doses are calculated from scatter-air ratios eliminating the need for empirical formulas. Calculated tissue-air ratios and percentage depth doses for elongated fields agree to within 2 per cent with measured data, eliminating the need for tables of equivalent squares. Calculated values for irregular fields also agree to within 2 per cent with measured data.

Complement C1-inactivator (C1-IA) in serum was determined in 423 individuals. The normal range for the concentration of C1-IA in serum was calculated from values in 94 blood donors and the concentrations in the sera of 329 patients were determined in relation to this range. A significant correlation was found between widespread malignant neoplastic disease and increased quantity of C1-IA in serum. Determination of C1-IA may be used to evaluate the extent to which a malignant disease is disseminated.

A comparison between two tracers, the one colloidal suspension of 198Au, the other 169Yb-labelled microspheres of 8 to 10 micron has been made concerning lymphatic and hematogenous spread from the submucosa in the rectum in dogs. Both tracers have, in principal, the same distribution. It was therefore considered that a colloidal suspension of 198Au is a useful tracer for functional anatomic investigations of lymph drainage.

Combination chemotherapy in advanced squamous carcinoma of the head and neck resulted in objective remission in 5 of 8 patients, with a median duration of 9 months. In 4 patients, the intravenous chemotherapy was supplemented by regional intra-arterial short-time infusion chemotherapy, by which one patient obtained a partial remission and 3 a static disease. The most important results of the methods used were the subjective improvements of the patients. The side-effects were acceptable, and no serious complications were observed.

The frequency of recurrences in a material of 463 patients with mammary carcinoma following treatment by surgery with or without postoperative roentgen or cobalt irradiation to the operation area and regional lymph nodes is analysed. Postoperative irradiation to the operation area seems to prevent the chest wall recurrences even in stage I mammary carcinoma.

The right hemithorax of rats was exposed to 1 kR of roentgen rays, the animals were killed at different times, and various physiologic and biochemic parameters (DNA, protein, collagen, sialic acid, lysosomal enzymes, fibrinolytic activity, peroxides and blood flow ratio between irradiated and non irradiated lung) were determined from 1 day until 11 months after irradiation. A decrease in relative blood flow was observed from 2 weeks until 11 months, a decrease in phospholipids from one to 3 months and a decrease in fibrinolytic activity from 1 day to 11 months after irradiation. At several times a decrease in sialic acid and cathepsin D was also noted. The changes are discussed with respect to the pathogenetic mechanisms of late lung damage.

A series of 203 consecutive patients with operable carcinoma of the breast was analysed with regard to correlations between a set of immunologic and clinical variables existing at the time of the diagnosis. No major correlations were revealed between immunologic variables on the one hand and clinical features or the course of the disease on the other. The well-known prognostic relevance of tumour size, involvement of the axilla and the histological grade of malignancy was evident.

A method capable of continuously recording the changes in the physiologic activity of ciliated cells during irradiation has been used to analyse the importance of photon energy for the early biologic effects of ionizing radiation. Gamma rays from 60Co and 50 kV roentgen rays were used. Important differences were demonstrated and conventional RBE values are not valid for early effects. The results are discussed and RBE for 50 kV roentgen rays has been calculated in respect to early effects of irradiation.

The rat femur diaphysis was exposed to local continuous irradiation with various constant dose-rates for different periods of time and examined after different observation times. The incidence of osteogenic sarcomas per cm2 appeared to be comparable to that reported for animals exposed to internal irradiation by bone-seeking isotopes which involves systemic effects. The site of origin in 5 rats was found to be in or near the endosteum. Malignant proliferation started after at least 180 days of irradiation. Tumour development was dependent upon continued irradiation of an endosteum which contained a thin layer of fibroblasts and a few apparently inactive osteoblasts and osteoclasts. No increased cellular activity and no indication of new bone, cartilage or fibrosis were evident before the tumours began to develop.

Pretreatment staging laparotomy in carcinoma of the uterine cervix has been advocated because surgical staging may detect disease not apparent clinically. An analysis of survival and local control data from previously reported large series of patients with carcinoma of the uterine cervix shows that surgical staging does not increase survival rates. It is likely that surgical staging may also increase morbidity from therapy.